Nearly three-quarters of American adults use social media, so quitting Facebook — committing “virtual identity suicide” — isn’t easy. So why are more people considering it?

Researchers surveyed 310 people who opted out of Facebook by participating in the (online!) QuitFacebookDay.com campaign begun by users angry over the company’s privacy policies. The changes included a service that allowed people to sign their friends up to groups without their permission. Since the May 31, 2010, quit date, 40,633 people have closed their Facebook accounts.

Intrigued by what motivated the quitters to go cold turkey on social media, the scientists, from the University of Vienna in Austria, compared them to 321 people who chose to stay.

Virtual suicide seemed to be an overwhelmingly male phenomenon— men made up a full 72% of those who opted out. Quitters were also generally older than those who stayed, with an average age of 31. Among those who stayed, 71% were women, with an average age of 24.

Not surprisingly, nearly half of the dropouts said they left because of fears about privacy and ethical concerns about how their personal data would be used. Many did not want their private information sold to advertisers or were worried about unauthorized disclosures to people they didn’t know. (Prior studies have found that older people tend to pay more attention to privacy issues than younger users, a trend that was supported by this data.)

“Given high profile stories such as WikiLeaks and the recent NSA surveillance reports, individual citizens are becoming increasingly more wary of cyber-related privacy concerns,” said Brenda Wiederhold, editor of the journal Cyberpsychology, Behavior and Social Networking, which published the study, in a statement.

The rest of the quitters left for a variety of reasons, with 14% saying they were dissatisfied with the site’s design and time-wasting features and 13% citing issues with Facebook “friendships,” such as superficiality or unwanted social pressure. Other analyses of social media users found that the relentless stream of perfectly curated baby pictures and happy social events to which you were not invited— coupled with a typical lack of openness about less wonderful moments — can lower self esteem, increase depression and afflict people with a terrible fear of missing out, an experience so common it’s earned an acronym — FOMO.

But 6% of Facebook quitters left because they feared they were becoming addicted to the site— and overall, the quitters had a higher score on symptoms of internet addiction than did those who chose to continue.

The study did not reveal, however, how many quitters “relapsed,” rejoining the site later.